From cf428b66d5779cbbbb08846ae526a9a5f1043863 Mon Sep 17 00:00:00 2001 From: Stephan Bergmann <sbergman@redhat.com> Date: Fri, 13 Jan 2012 11:38:24 +0100 Subject: [PATCH] Confine JDBC driver to thread-affine apartment for Java 6 performance ... so that the massive number of the JDBC driver's calls to JNI Attach/Detach- CurrentThread are guaranteed not to happen on the main thread (where they are extremely expensive, see <http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6978641> "Fix for 6929067 introduces additional overhead in thread creation/termination paths"). (cherry-picked from <http://cgit.freedesktop.org/libreoffice/core/commit/?id=bb59742bcf4883af5876a2ffadcc4a689e414b60>) --- connectivity/source/drivers/jdbc/jservices.cxx | 10 +++++++++- 1 files changed, 9 insertions(+), 1 deletions(-) diff --git a/connectivity/source/drivers/jdbc/jservices.cxx b/connectivity/source/drivers/jdbc/jservices.cxx index aebe76b..1a438be 100644 --- a/connectivity/source/drivers/jdbc/jservices.cxx +++ b/connectivity/source/drivers/jdbc/jservices.cxx @@ -93,7 +93,15 @@ component_getImplementationEnvironment( uno_Environment ** /*ppEnv*/ ) { - *ppEnvTypeName = CPPU_CURRENT_LANGUAGE_BINDING_NAME; + // Recent Java 6 VMs make calls to JNI Attach/DetachCurrentThread (which + // this code does extensively) very expensive. A follow-up JVM fix reduced + // the overhead significantly again for all threads but the main thread. So + // a quick hack to improve performance of this component again is to confine + // it in the affine apartment (where all code will run on a single, + // dedicated thread that is guaranteed no to be the main thread). However, + // a better fix would still be to redesign the code so that it does not call + // Attach/DetachCurrentThread so frequently: + *ppEnvTypeName = CPPU_CURRENT_LANGUAGE_BINDING_NAME ":affine"; } //--------------------------------------------------------------------------------------- -- 1.7.7.5